Extended Restitution Between Sessions Does Not Enhance the Benefits of 12 Weeks Exercise-Based Treatment for Patellar Tendinopathy: A Randomized Controlled Clinical Trial (The TEREX Trial).

Loading intervention is the predominant treatment strategy for tendinopathy and the response may depend on restitution time between loading exposure. Therefore, the purpose of this study was to investigate if a 12-week exercise-based rehabilitation regime for patellar tendinopathy is influenced by restitution time. We hypothesized that longer restitution would yield greater improvements in clinical outcomes, tissue structure, and function compared to shorter restitution. Fifty-two participants with chronic patellar tendinopathy were randomized to a short restitution group (SR, 3 exercise days/week) or an extended restitution group (ER, 1 exercise day/week). For both groups, each session consisted of resistance exercises (Leg press and knee extension) with a load starting at ~60% of 1 RM and progressing to ~75% of 1 RM and impact activities (running and jumping), restricted in both groups. Function and symptoms (VISA-P), tendon pain during activity (NRS), tendon function (functional tests), and ultrasound (tendon vascularization and swelling) were assessed before and after the intervention. Self-reported improvement and satisfaction with function and treatment were measured at week 12. The results revealed that ER was not superior to SR for any of the outcomes. Both groups attained significant improvements in clinical outcomes and muscular strength. Conversely, there were no improvements in jumping height or tendon structure. Moreover, there were no group differences in self-reported improvement or satisfaction with function or treatment. In conclusion, there was no superior effect of 1 exercise day/week compared to 3 exercise days/week. Both groups demonstrated equal clinical and muscular strength improvement after 12 weeks without any improvement in structure or jumping performance. No group differences were found in self-reported improvement or satisfaction with function or treatment at week 12.